Fig. 3

Effect of contamination on the viability of bacteria inoculated on face mask pieces. Bacteria were inoculated on face mask pieces in the presence of contaminants and incubated at 37 °C for 1 day. (A) Artificial sweat and artificial sebum solutions, (C) artificial saliva and peptone water, and (E) foundation powder and squalene were used to contaminate Staphylococcus aureus inoculated on face mask pieces. (B) Artificial sweat and artificial sebum solutions, (D) artificial saliva and peptone water, and (F) foundation powder and squalene were used to contaminate S. epidermidis on face mask pieces. PBS: phosphate-buffered saline. Control: inoculum suspended in PBS in microtubes. *p < 0.05 vs. PBS. CFU: colony-forming unit, n.s.: no significant difference.